The main constituents of pearls are
A). Calcium Oxide and Ammonium Chloride
B). Calcium Carbonate and Magnesium Carbonate
C). Aragonite and Conchiolin
D). Ammonium Sulphate and Sodium Carbonate
Which of the following is not an isotope of hydrogen?
A). Tritium
B). Deuterium
C). Protium
D). Yttrium
Water is a good solvent of ionic salts because:
A). It has a high specific heat
B). It has no colour
C). It has a high dipole moment
D). It has a high boiling point
Bell metal is an alloy of
A). Nickel and Copper
B). Zinc and Copper
C). Brass and Nickel
D). Tin and Copper
Which metal pollute the air of a big city?
A). Copper
B). Chromium
C). Lead
D). Cadmium